Discover Credit Card Complaint

Discover Credit card department,

Payoff process Texas

Discover has misreported a balance on a credit card that was paid close to 4 years ago. I pulled up my credit report and it is still showing a balance even though I already paid it. This has caused stress on my credit report. I 've written them a letter and disputed it on my credit report however nothing has been resolved. Please help me get this account removed or reduced to what is accurate.